Elastic wave devices

Abstract

To provide an elastic wave device capable of suppressing electromagnetic coupling between a signal wiring and a signal terminal.SOLUTION: An acoustic wave device 100 includes a substrate 10 having an upper surface 10a and a lower surface, a plurality of terminals 15 provided on the lower surface, a plurality of elastic resonators 13 which are provided on the upper surface 10a and connected between a transmission terminal Tx and a common terminal Ant out of the plurality of terminals 15, a signal wiring 14a which is provided on the upper surface 10a and connected to the elastic wave resonators 13, and a metal layer 40 which is provided between the upper surface 10a and the signal wiring 14a in a region 42 where a portion 60 of the signal wiring 14a connected to the common terminal Ant without passing through the elastic wave resonators 13 is overlapped with a reception terminal Rx which is a signal terminal other than the common terminal Ant to which the portion 60 is connected without passing through the elastic wave resonators 13 in the plurality of terminals 15, and is electrically connected to a ground terminal Gnd of the plurality of terminals 15.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to an elastic wave device.

Background Art

[0002] It is known to provide wiring and a shield electrode adjacent to the wiring on the upper surface of a substrate, and suppress electromagnetic coupling between the wirings by the shield electrode (for example, Patent Document 1). Further, an elastic wave device is known in which a plurality of elastic wave elements are provided on the upper surface of a substrate, and terminals electrically connected to the plurality of elastic wave elements are provided on the lower surface (for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In an elastic wave device in which signal wirings connected to a plurality of elastic wave elements are provided on the upper surface of a substrate and signal terminals are provided on the lower surface of the substrate, electromagnetic field coupling may occur between the signal wirings and the signal terminals, resulting in deterioration of characteristics.

[0005] The present invention has been made in view of the above problems, and an object thereof is to suppress electromagnetic field coupling between a signal wiring and a signal terminal.

Means for Solving the Problems

[0006] The present invention provides a first surface and a second surface opposite to the first surface A first substrate having, a plurality of terminals provided on the second on the surface and the first on the surfaceA plurality of first elastic wave resonators are provided and connected between the first signal terminal and the second signal terminal among the plurality of terminals, and the first on the surface A signal wiring is provided and connected to the plurality of first elastic wave resonators, and the signal wiring does not go through the plurality of first elastic wave resonators to the first signal terminal or the second signal terminal Either one of the signal terminals A first part that connects to and among the plurality of terminals Either of the aforementioned signal terminals In at least one of the regions, the first region overlaps with the signal terminals other than the first, and the second region overlaps with the signal terminals among the plurality of terminals, where the second portion of the signal wiring that connects to the first and second signal terminals via at least one of the plurality of first elastic wave resonators overlaps with the signal terminals among the plurality of terminals. surface A metal layer is provided between the signal wiring and the ground terminal of the plurality of terminals, The device comprises a sealing portion provided on the first surface surrounding the plurality of first elastic wave resonators, sealing the gap between the plurality of first elastic wave resonators, wherein the sealing portion is electrically connected to the ground terminal, and the metal layer is electrically connected to the ground terminal by contacting the sealing portion on the first surface. It is an elastic wave device.

[0008] In the above configuration, the metal layer can be provided near the corner of the sealing portion in a plan view and connected to the sealing portion at at least two locations on either side of the corner.

[0009] In the above configuration, the first substrate is the second surface A support substrate having the above, and the first bonded to the support substrate surface The system comprises a piezoelectric substrate having a , the sealing portion being provided in an area on the support substrate where the piezoelectric substrate is not present, and the metal layer being provided extending from the piezoelectric substrate to the support substrate and the sealing portion being provided contact This configuration can be implemented.

[0010] In the above configuration, a plurality of second elastic wave resonators are provided, connected between the first signal terminal and the third signal terminal among the plurality of terminals, wherein the plurality of first elastic wave resonators form a first filter connected between the first signal terminal and the second signal terminal, and the plurality of second elastic wave resonators form a second filter connected between the first signal terminal and the third signal terminal.

[0011] In the above configuration, the first region is the region where the first portion and the third signal terminal overlap, and the metal layer is the first of the first substrate in the first region. surface It can be configured to be provided between the signal wiring and the signal wiring.

[0012] In the above configuration, the second region is the region where the second portion and the first signal terminal overlap, and the metal layer is the first of the first substrate in the second region. surface It can be configured to be provided between the signal wiring and the signal wiring.

[0013] In the above configuration, the first substrate surface The device may be configured to include a second substrate positioned opposite to it with an air gap in between, and the plurality of second elastic wave resonators may be provided on the second substrate.

[0014] In the above configuration, the first signal terminal is a common terminal, the second signal terminal is a transmit terminal, the third signal terminal is a receive terminal, the first filter is a transmit filter connected between the common terminal and the transmit terminal, and the second filter is a receive filter connected between the common terminal and the receive terminal.

[0015] In the above configuration, an insulating layer may be provided between the metal layer and the signal wiring to insulate the metal layer from the signal wiring.

[0016] The present invention is the first surface and the first surface The opposite of the second surface A substrate having the following, and the second on the surface Multiple terminals provided therein, and the first on the surface Multiple elastic wave resonators provided in and the first on the surface In the region where the signal wiring connected to the plurality of elastic wave resonators, the signal terminal among the plurality of terminals, and the portion of the signal wiring that has a different potential from the signal terminal overlap, the first surfacea metal layer provided between the signal wiring and the ground terminal among the plurality of terminals and electrically connected to the ground terminal; The system comprises a sealing portion provided on the first surface surrounding the plurality of elastic wave resonators, sealing the gap between the plurality of elastic wave resonators, the sealing portion being electrically connected to the ground terminal, and the metal layer being electrically connected to the ground terminal by contacting the sealing portion on the first surface. It is a surface acoustic wave device.

Advantages of the Invention

[0017] According to the present invention, electromagnetic field coupling between the signal wiring and the signal terminal can be suppressed.

Brief Description of the Drawings

[0018] [Figure 1] FIG. 1 is a circuit diagram of the surface acoustic wave device according to Embodiment 1. [Figure 2] FIG. 2 is a cross-sectional view of the surface acoustic wave device according to Embodiment 1. [Figure 3] FIG. 3(a) is a plan view when the surface acoustic wave resonator is a surface acoustic wave resonator, and FIG. 3(b) is a cross-sectional view when the surface acoustic wave resonator is a piezoelectric thin film resonator. [Figure 4] FIGS. 4(a) and 4(b) are plan views of the substrate in the surface acoustic wave device according to Embodiment 1. [Figure 5] FIG. 5(a) is a plan view near the receiving terminal, and FIGS. 5(b) to 5(d) are exploded plan views of the signal wiring, the insulating layer, and the metal layer. [Figure 6] FIGS. 6(a) and 6(b) are plan views of the substrate in the surface acoustic wave device according to a modification of Embodiment 1. [Figure 7] FIG. 7 is a cross-sectional view of the surface acoustic wave device according to the comparative example. [Figure 8] FIGS. 8(a) and 8(b) are plan views of the substrate in the surface acoustic wave device according to the comparative example. [Figure 9] FIGS. 9(a) and 9(b) are plan views of the substrate in Model 1 used for the simulation. [Figure 10] FIG. 10 is a diagram showing the simulation results of the isolation characteristics of Models 1 and 2. [Figure 11] FIGS. 11(a) and 11(b) are plan views of the substrate in the surface acoustic wave device according to Embodiment 2. [Modes for carrying out the invention]

[0019] The embodiments of the present invention will be described below with reference to the drawings. [Examples]

[0020] Figure 1 is a circuit diagram of the elastic wave device 100 according to Embodiment 1. As shown in Figure 1, the elastic wave device 100 is a duplexer and comprises a transmit filter 70 connected between a common terminal Ant and a transmit terminal Tx, and a receive filter 74 connected between a common terminal Ant and a receive terminal Rx. The transmit filter 70 outputs the transmit band signal of the high-frequency signal input to the transmit terminal Tx to the common terminal Ant, and suppresses signals in other frequency bands. The receive filter 74 outputs the receive band signal of the high-frequency signal input to the common terminal Ant to the receive terminal Rx, and suppresses signals in other frequency bands.

[0021] The transmit filter 70 is a ladder-type filter. The transmit filter 70 comprises series resonators S11 and S12 connected in series between the transmit terminal Tx and the common terminal Ant, and parallel resonators P11, P12, and P13 connected in parallel. The series resonators S11 and S12 are located in the series path 72 between the transmit terminal Tx and the common terminal Ant. One end of the parallel resonators P11, P12, and P13 is connected to the series path 72, and the other end is connected to the ground terminal Gnd.

[0022] The receiving filter 74 is a ladder-type filter. The receiving filter 74 comprises series resonators S21 and S22 connected in series between the common terminal Ant and the receiving terminal Rx, and parallel resonators P21, P22, and P23 connected in parallel. The series resonators S21 and S22 are located in the series path 76 between the common terminal Ant and the receiving terminal Rx. The parallel resonators P21, P22, and P23 have one end connected to the series path 76 and the other end connected to the ground terminal Gnd.

[0023] Figure 2 is a cross-sectional view of the elastic wave device 100 according to Embodiment 1. As shown in Figure 2, a substrate 20 is provided on a substrate 10, and a lid 30 is provided on the substrate 20. Substrate 10 has a support substrate 11 and a piezoelectric substrate 12 bonded to the support substrate 11. Similarly, substrate 20 has a support substrate 21 and a piezoelectric substrate 22 bonded to the support substrate 21. The support substrates 11 and 21 are, for example, sapphire substrates, alumina substrates, spinel substrates, quartz substrates, crystal substrates, or silicon substrates, and are single-crystal substrates, polycrystalline substrates, or sintered substrates. The piezoelectric substrates 12 and 22 are, for example, lithium tantalate substrates or lithium niobate substrates, and are single-crystal substrates. The thickness of the piezoelectric substrates 12 and 22 is, for example, 0.5 μm to 30 μm, and is, for example, less than or equal to the wavelength λ of the elastic wave that excites the elastic wave resonators 13 and 23.

[0024] An elastic wave resonator 13 and wiring 14 are provided on the upper surface 10a of substrate 10. An elastic wave resonator 23 and wiring 24 are provided on the upper surface 20a of substrate 20. A shielding layer 28 is provided on the lower surface 20b of substrate 20. The shielding layer 28 has the function of shielding electromagnetic waves between elastic wave resonators 13 and 23. The shielding layer 28 includes, for example, a conductive metal layer such as a copper layer, silver layer, tungsten layer, aluminum layer, or titanium layer, or a magnetic metal layer such as an iron layer, nickel layer, or iron-nickel alloy layer (Kovar layer). The thickness of the shielding layer 28 is preferably equal to or greater than the skin thickness of the electromagnetic waves to be shielded. A plurality of terminals 15 are provided on the lower surface 10b of substrate 10. The terminals 15 are foot pads for connecting the elastic wave resonators 13 and 23 to the outside.

[0025] A via wiring 16 is provided that penetrates the substrate 10. The via wiring 16 electrically connects wiring 14 and terminal 15. Electrical connection means that the connection is such that there is conductivity in either DC or AC (the same applies hereafter). Wiring 14, terminal 15, and via wiring 16 are metal layers such as a copper layer, aluminum layer, or gold layer. Terminal 15 includes a common terminal Ant, a transmit terminal Tx, a receive terminal Rx, and a ground terminal Gnd, but in Figure 2 only the receive terminal Rx and the ground terminal Gnd are shown.

[0026] A via wiring 26 is provided that penetrates the substrate 20. The via wiring 26 is connected to the via wiring 16 via a pillar 17. The wiring 24 and the via wiring 26 are metal layers, such as a copper layer, an aluminum layer, or a gold layer. The pillar 17 is a metal layer, such as a copper layer, a gold layer, a silver layer, or an aluminum layer.

[0027] The upper surface 10a of substrate 10 and the lower surface 20b of substrate 20 face each other with an air gap 32 in between. A sealing portion 34 is provided between substrate 10 and substrate 20 so as to surround the elastic wave resonator 13 and the wiring 14. The sealing portion 34 is provided in the region where the piezoelectric substrate 12 at the periphery of the support substrate 11 has been removed. The sealing portion 34 has an annular metal layer 34a and a solder layer 34b. The solder layer 34b joins the annular metal layer 34a and the shield layer 28. The sealing portion 34 seals the elastic wave resonator 13 and the wiring 14 in the air gap 32. The annular metal layer 34a is a metal layer including, for example, a nickel layer, a copper layer, or a gold layer. The solder layer 34b is, for example, an AuSn layer. The width of the sealing portion 34 is, for example, 50 μm to 200 μm. The sealing portion 34 is electrically connected to the ground terminal Gnd via a via wiring 16. The shield layer 28 is electrically connected to the sealing portion 34 and electrically connected to the ground terminal Gnd.

[0028] The lid 30 and the upper surface 20a of the substrate 20 face each other with a gap 33 in between. A sealing portion 36 is provided between the substrate 20 and the lid 30 so as to surround the elastic wave resonator 23 and the wiring 24. The sealing portion 36 is provided in the area where the piezoelectric substrate 22 has been removed from the periphery of the upper surface of the support substrate 21. The sealing portion 36 has an annular metal layer 36a and a solder layer 36b. The solder layer 36b joins the annular metal layer 36a and the lid 30. The sealing portion 36 seals the elastic wave resonator 23 and the wiring 24 in the gap 33. The annular metal layer 36a is a metal layer including, for example, a nickel layer, a copper layer, or a gold layer. The solder layer 36b is, for example, an AuSn layer. The lid 30 is an insulating plate such as a sapphire substrate or a metal plate such as a Kovar substrate. The width of the sealing portion 36 is, for example, 50 μm to 200 μm. The sealing portion 36 may be electrically connected to the shielding layer 28 by via wiring 26 that penetrates the substrate 20. This allows the sealing portion 36 and the lid 30 to be electrically connected to the ground terminal Gnd.

[0029] Wiring 14 includes signal wiring 14a connecting the transmit terminal Tx to the elastic wave resonator 13, the common terminal Ant to the elastic wave resonator 13, and the two elastic wave resonators 13, and ground wiring 14b connecting the ground terminal Gnd to the elastic wave resonator 13. Similarly, wiring 24 includes signal wiring 24a connecting the common terminal Ant to the elastic wave resonator 23, the receive terminal Rx to the elastic wave resonator 23, and the two elastic wave resonators 23, and ground wiring 24b connecting the ground terminal Gnd to the elastic wave resonator 23.

[0030] In the region 42 where the signal wiring 14a and the receiving terminal Rx overlap in a plan view, a metal layer 40 is provided on the upper surface 10a of the substrate 10. The metal layer 40 is provided from the piezoelectric substrate 12 to the support substrate 11, with its end fitting between the support substrate 11 and the sealing portion 34. As a result, the metal layer 40 is in contact with the sealing portion 34 on the support substrate 11. Therefore, the metal layer 40 is electrically connected to the ground terminal Gnd. The metal layer 40 has the function of shielding electromagnetic waves between the signal wiring 14a and the receiving terminal Rx in region 42. The metal layer 40 is, for example, a conductive metal layer such as a copper layer, silver layer, tungsten layer, aluminum layer, or titanium layer, or a magnetic metal layer such as an iron layer, nickel layer, or iron-nickel alloy layer (Kovar layer). Preferably, the thickness of the metal layer 40 is greater than or equal to the skin thickness of the electromagnetic waves to be shielded.

[0031] An insulating layer 46 is provided between the metal layer 40 and the signal wiring 14a to insulate the metal layer 40 from the signal wiring 14a. The insulating layer 46 is, for example, a resin insulating layer such as polyimide resin or epoxy resin, or an inorganic insulating layer such as silicon oxide, silicon nitride, or aluminum oxide. The insulating layer 46 may also have air pockets. The thickness of the insulating layer 46 is, for example, 1 μm to 10 μm.

[0032] Examples of elastic wave resonators 13 and 23 will be described using Figures 3(a) and 3(b). Figure 3(a) is a plan view when the elastic wave resonators 13 and 23 are surface acoustic wave resonators. As shown in Figure 3(a), an IDT (Interdigital Transducer) 50 and a reflector 51 are formed on the piezoelectric substrates 12 and 22. The IDT 50 comprises a pair of opposing comb-shaped electrodes 52. The comb-shaped electrodes 52 comprise a plurality of electrode fingers 53 and a busbar 54 connecting the plurality of electrode fingers 53. The reflector 51 is provided on both sides of the IDT 50. The IDT 50 excites surface acoustic waves in the piezoelectric substrates 12 and 22. The IDT 50 and the reflector 51 are formed of, for example, an aluminum film or a copper film. As shown in Figure 2, piezoelectric substrates 12 and 22 may be bonded to support substrates 11 and 21, respectively, or the support substrates 11 and 21 may not be provided, and substrates 10 and 20 may consist of piezoelectric substrates 12 and 22 individually. An insulating film such as a silicon oxide film or an aluminum oxide film may be provided between the support substrates 11 and 21 and the piezoelectric substrates 12 and 22. A protective film or temperature compensation film may be provided on substrates 10 and 20 to cover the IDT 50 and the reflector 51.

[0033] Figure 3(b) is a cross-sectional view of the case where the elastic wave resonators 13 and 23 are piezoelectric thin film resonators. As shown in Figure 3(b), a piezoelectric film 56 is provided on the substrates 10 and 20. A lower electrode 55 and an upper electrode 57 are provided so as to sandwich the piezoelectric film 56. A gap 59 is formed between the lower electrode 55 and the substrates 10 and 20. The region where the lower electrode 55 and the upper electrode 57 face each other with at least a portion of the piezoelectric film 56 in between is the resonance region 58. The lower electrode 55 and the upper electrode 57 within the resonance region 58 excite elastic waves in thickness longitudinal vibration mode within the piezoelectric film 56. The substrates 10 and 20 are, for example, sapphire substrates, spinel substrates, alumina substrates, glass substrates, quartz substrates, or silicon substrates. The lower electrode 55 and the upper electrode 57 are, for example, metal films such as ruthenium films. The piezoelectric film 56 is, for example, an aluminum nitride film. Instead of the gap 59, an acoustic reflective film that reflects elastic waves may be provided.

[0034] The elastic wave resonators 13 and 23 include electrodes for exciting elastic waves. Therefore, as shown in Figure 2, elastic wave resonators 13 are covered by a gap 32 and elastic wave resonators 23 are covered by a gap 33 so as not to hinder the excitation of elastic waves.

[0035] Figures 4(a) and 4(b) are plan views of the substrates 10 and 20 in the elastic wave device 100 according to Embodiment 1. Figure 4(a) is a plan view of the top surface 20a of substrate 20 as seen from above, and Figure 4(b) is a plan view of the top surface 10a of substrate 10 as seen from above. In Figure 4(b), the terminal 15 provided on the bottom surface 10b of substrate 10 is shown as a dashed line through a transparent view, and in Figures 4(a) and 4(b), the signal lines 14a, 24a and the ground lines 14b, 24b are hatched for clarity (the same applies to similar figures below).

[0036] As shown in Figures 4(a) and 4(b), an elastic wave resonator 23, signal wiring 24a, and ground wiring 24b are provided on the upper surface 20a of the substrate 20. The elastic wave resonator 23 is a surface acoustic wave resonator comprising, for example, an IDT 50 and a reflector 51. The signal wiring 24a is connected between the common terminal Ant and the elastic wave resonator 23, between the receiving terminal Rx and the elastic wave resonator 23, and between the two elastic wave resonators 23. The ground wiring 24b is connected between the ground terminal Gnd and the elastic wave resonator 23. A sealing portion 36 is provided on the periphery of the substrate 20. The elastic wave resonator 23 includes series resonators S21 and S22 and parallel resonators P21, P22, and P23 that constitute the receiving filter 74.

[0037] An elastic wave resonator 13, signal wiring 14a, and ground wiring 14b are provided on the upper surface 10a of the substrate 10. The elastic wave resonator 13 is a surface acoustic wave resonator comprising, for example, an IDT 50 and a reflector 51. The signal wiring 14a is connected between the transmit terminal Tx and the elastic wave resonator 13, between the common terminal Ant and the elastic wave resonator 13, and between the two elastic wave resonators 13. The ground wiring 14b is connected between the ground terminal Gnd and the elastic wave resonator 13. A sealing portion 34 is provided on the periphery of the substrate 10. The elastic wave resonator 13 includes series resonators S11 and S12 and parallel resonators P11, P12, and P13 that constitute the transmit filter 70.

[0038] Multiple terminals 15 are provided on the lower surface 10b of the circuit board 10. The multiple terminals 15 include a common terminal Ant, a transmit terminal Tx, a receive terminal Rx, and a ground terminal Gnd. The common terminal Ant is located in the center of one of a pair of opposing sides of the lower surface 10b, while the transmit terminal Tx and the receive terminal Rx are located at the ends of the other side. As a result, the common terminal Ant, the transmit terminal Tx, and the receive terminal Rx are spaced far apart from each other.

[0039] The series resonators S21 and S22 that constitute the receiving filter 74 are connected in series between the common terminal Ant and the receiving terminal Rx via signal wiring 24a, via wiring 26, pillar 17, and via wiring 16. The parallel resonators P21, P21, and P23 that constitute the receiving filter 74 are connected in parallel between the common terminal Ant and the receiving terminal Rx, with one end connected to signal wiring 24a and the other end connected to the ground terminal Gnd via ground wiring 24b, via wiring 26, pillar 17, and via wiring 16.

[0040] The series resonators S11 and S12 that constitute the transmit filter 70 are connected in series between the transmit terminal Tx and the common terminal Ant via signal wiring 14a and via wiring 16. The parallel resonators P11, P12 and P13 that constitute the transmit filter 70 are connected in parallel between the transmit terminal Tx and the common terminal Ant, with one end connected to signal wiring 14a and the other end connected to the ground terminal Gnd via ground wiring 14b and via wiring 16.

[0041] The portion 60 of the signal wiring 14a that connects the common terminal Ant to the series resonator S12 overlaps with the receiving terminal Rx in a plan view. The region where portion 60 of the signal wiring 14a and the receiving terminal Rx overlap in a plan view is indicated by region 42. A metal layer 40 and an insulating layer 46 are provided between the signal wiring 14a and the upper surface 10a of the substrate 10 so as to include region 42.

[0042] Figure 5(a) is a plan view of the vicinity of the receiving terminal Rx, and Figures 5(b) to 5(d) are exploded plan views of the signal wiring 14a, the insulating layer 46, and the metal layer 40. As shown in Figures 5(a) to 5(d), the metal layer 40 is provided between the upper surface 10a of the substrate 10 and the signal wiring 14a so as to cover the region 42 where the portion 60 connecting the common terminal Ant and the series resonator S12 of the signal wiring 14a overlaps with the receiving terminal Rx. It is preferable that the metal layer 40 completely covers the region 42, but it is also acceptable if it does not cover a part of the region 42. The metal layer 40 is in contact with the sealing portion 36 at two locations 41a and 41b, which are located on either side of the corner 37 of the sealing portion 34.

[0043] The insulating layer 46 is provided between the metal layer 40 and the signal wiring 14a, covering the area where the metal layer 40 and the signal wiring 14a overlap in a plan view. Preferably, the insulating layer 46 is provided so as to completely cover the area where the metal layer 40 and the signal wiring 14a overlap in a plan view. This ensures insulation between the metal layer 40 and the signal wiring 14a.

[0044] [Manufacturing method] An example of a manufacturing method for the elastic wave device 100 according to Example 1 will be described. First, substrates 10 and 20 are formed separately. Substrate 10 is formed by bonding a piezoelectric substrate 12 onto a support substrate 11 on which via wiring 16 is formed, and then thinning the piezoelectric substrate 12 to a desired thickness by polishing or grinding. For bonding the support substrate 11 and the piezoelectric substrate 12, for example, a direct bonding method using room temperature bonding is used by activating the surface of the support substrate 11 and the surface of the piezoelectric substrate 12. Next, the piezoelectric substrate 12 is etched to process it into a desired shape and an elastic wave resonator 13 is formed on the piezoelectric substrate 12. After that, a metal layer 40, an insulating layer 46 and wiring 14 are formed. Next, a sealing portion 34 is formed on the periphery of substrate 10 and pillars 17 are formed on the via wiring 16. The formation of the elastic wave resonator 13, wiring 14, via wiring 16, pillars 17, sealing portion 34, metal layer 40 and insulating layer 46 is done using generally known methods.

[0045] Similar to substrate 10, the piezoelectric substrate 22 is bonded to a support substrate 21 on which via wiring 26 is formed. Then, the piezoelectric substrate 22 is thinned to a desired thickness and processed into a desired shape. An elastic wave resonator 23 is formed on the piezoelectric substrate 22, wiring 24 is formed to connect to the elastic wave resonator 23, and a sealing portion 36 is formed on the periphery of the substrate 20. After that, a lid 30 is mounted on the sealing portion 36. As a result, the elastic wave resonator 23 is sealed in the gap 33 formed between the substrate 20 and the lid 30. Next, the support substrate 21 is thinned to a desired thickness by polishing or grinding, and then a shield layer 28 is formed on the lower surface 20b of the substrate 20.

[0046] Next, the substrate 20 is mounted on the sealing portion 34 of the substrate 10 and the pillar 17. As a result, the elastic wave resonator 13 formed on the substrate 10 is sealed in the gap 32 formed between the substrate 10 and the substrate 20. After that, the support substrate 11 is thinned to the desired thickness by polishing or grinding, and then a plurality of terminals 15 are formed on the lower surface 10b of the substrate 10.

[0047] [Differentiation] The circuit diagram and cross-sectional view of the elastic wave device 110 according to the modified example of Example 1 are the same as those in Figures 1 and 2 of Example 1, so their description is omitted. Figures 6(a) and 6(b) are plan views of the substrates 10 and 20 in the elastic wave device 110 according to the modified example of Example 1. Figure 6(a) is a plan view of the top surface 20a of the substrate 20 seen from above, and Figure 6(b) is a plan view of the top surface 10a of the substrate 10 seen from above. As shown in Figures 6(a) and 6(b), in the modified example of Example 1, the portion 62 of the signal wiring 14a that connects the transmitting terminal Tx and the series resonator S11 overlaps with the receiving terminal Rx in a plan view. The metal layer 40 is provided between the top surface 10a of the substrate 10 and the signal wiring 14a so as to cover the region 42a where the portion 62 of the signal wiring 14a that connects the transmitting terminal Tx and the series resonator S11 overlaps with the receiving terminal Rx, similar to Example 1. Similar to Example 1, the insulating layer 46 is provided between the metal layer 40 and the signal wiring 14a so as to cover the area where the metal layer 40 and the signal wiring 14a overlap in a plan view. The other configurations are the same as in Example 1, so their description is omitted.

[0048] [Comparative Example] The circuit diagram of the comparative example elastic wave device 500 is the same as that of Figure 1 in Example 1, so its description is omitted. Figure 7 is a cross-sectional view of the comparative example elastic wave device 500. Figures 8(a) and 8(b) are plan views of the substrates 10 and 20 in the comparative example elastic wave device 500. As shown in Figures 7, 8(a), and 8(b), in the comparative example elastic wave device 500, the metal layer 40 is not provided in the region 42 where the portion 60 connecting the common terminal Ant and the series resonator S12 of the signal wiring 14a and the receiving terminal Rx overlap in a plan view, and consequently, the insulating layer 46 is also not provided. The other configurations are the same as in Example 1, so their description is omitted.

[0049] In the comparative example, the potential of the portion 60 connecting the common terminal Ant and the series resonator S12 in the signal wiring 14a is different from that of the receiving terminal Rx. Therefore, in the region 42 where this portion 60 and the receiving terminal Rx overlap, electromagnetic field coupling between the signal wiring 14a and the receiving terminal Rx tends to be large. This may lead to a deterioration of the isolation characteristics. The signal wirings 14a and 24a are lines through which high-frequency signals propagate, and their potential changes each time they pass through the elastic wave resonators 13 and 23. As a result, the potential of the portion 60 connecting the common terminal Ant and the series resonator S12 in the signal wiring 14a is different from that of the receiving terminal Rx. Note that the ground wirings 14b and 24b are connected to the ground terminal Gnd, and therefore are at ground potential. In contrast, in Example 1 and its modified form, a metal layer 40 is provided between the upper surface 10a of the substrate 10 and the signal wiring 14a in the region 42 where the portion 60 connecting the common terminal Ant and the series resonator S12 of the signal wiring 14a overlaps with the receiving terminal Rx. Since the metal layer 40 is electrically connected to the ground terminal Gnd, electromagnetic field coupling between the signal wiring 14a and the receiving terminal Rx can be suppressed. Therefore, deterioration of isolation characteristics can be suppressed.

[0050] [simulation] The isolation characteristics of Model 1, which corresponds to Example 1, and Model 2, which corresponds to the comparative example, were simulated. The cross-sectional view of Model 1 is the same as in Figure 1, and the cross-sectional view of Model 2 is the same as in Figure 7. Figures 9(a) and 9(b) are plan views of substrates 10 and 20 in Model 1 used in the simulation.

[0051] As shown in Figures 9(a) and 9(b), in Model 1, an elastic wave resonator 23 is provided on the upper surface 20a of the substrate 20, which includes series resonators S21, S22, S23, S24, and S25 that constitute the receiving filter 74, and parallel resonators P21, P22, P23, and P24. An elastic wave resonator 13 is provided on the upper surface 10a of the substrate 10, which includes series resonators S11, S12, and S13 that constitute the transmitting filter 70, and parallel resonators P11, P12a, P12b, P13a, P13b, and P14. A common terminal Ant, a transmitting terminal Tx, a receiving terminal Rx, and a ground terminal Gnd are provided on the lower surface 10b of the substrate 10.

[0052] The portion 60 of the signal wiring 14a connecting the common terminal Ant and the series resonator S13 overlaps with the receiving terminal Rx in a plan view. The signal wiring 14a was made larger to increase its overlap with the receiving terminal Rx so that the effect of electromagnetic field coupling between the signal wiring 14a and the receiving terminal Rx would be more pronounced. A metal layer 40 is provided between the upper surface 10a of the substrate 10 and the signal wiring 14a so as to completely cover the region 42 where the portion 60 of the signal wiring 14a connecting the common terminal Ant and the series resonator S13 overlaps with the receiving terminal Rx. The metal layer 40 is electrically connected to the ground terminal Gnd by connecting to the sealing portion 34. An insulating layer 46 is provided between the signal wiring 14a and the metal layer 40 to insulate them from each other.

[0053] Model 2 has the same structure as Model 1 shown in Figures 9(a) and 9(b), except that it does not have a metal layer 40 and an insulating layer 46.

[0054] The simulation conditions are as follows: Regarding the lower circuit board Support substrate 11: Sapphire substrate with a thickness of 75 μm Piezoelectric substrate 12: Lithium tantalate substrate with a thickness of 3 μm Wiring 14 on metal layer 40: Laminated film of a titanium layer with a thickness of 0.2 μm and a gold layer with a thickness of 1 μm Wiring 14 other than on metal layer 40: Laminated film of a titanium layer with a thickness of 0.03 μm, an aluminum layer with a thickness of 0.1 μm, a titanium layer with a thickness of 0.2 μm, and a gold layer with a thickness of 1 μm. Metal layer 40: A titanium layer with a thickness of 0.03 μm and an aluminum layer with a thickness of 0.1 μm. Insulating layer 46: Polyimide layer with a thickness of 3 μm. Via wiring 16: Copper layer with a top diameter of 40 μm and a bottom diameter of 10 μm. Terminal 15: Laminated film consisting of a nickel layer with a thickness of 5 μm and a copper layer with a thickness of 2.4 μm. Sealing portion 34: A laminated film consisting of a nickel layer with a thickness of 2.5 μm and a copper layer with a thickness of 20 μm, with a width of 23 μm. Pillar 17: A laminated film consisting of a nickel layer with a thickness of 2.5 μm and a copper layer with a thickness of 20 μm, with a width of 23 μm. Upper circuit board Support substrate 21: Sapphire substrate with a thickness of 75 μm Piezoelectric substrate 22: Lithium tantalate substrate with a thickness of 3 μm Wiring 24: Laminated film consisting of a titanium layer with a thickness of 0.02 μm, an aluminum layer with a thickness of 0.11 μm, a titanium layer with a thickness of 0.2 μm, and a gold layer with a thickness of 1 μm. Via wiring 26: Copper layer with a top diameter of 40 μm and a bottom diameter of 10 μm. Sealing portion 36: A laminated film consisting of a copper layer with a thickness of 20 μm and a nickel layer with a thickness of 2.5 μm, with a width of 23 μm. Lid 30: Kovar plate with a thickness of 30 μm Shielding layer 28: A copper layer with a thickness of 3 μm.

[0055] Figure 10 shows the simulation results of the isolation characteristics of Models 1 and 2. As shown in Figure 10, Model 1, which corresponds to Example 1, showed improved isolation characteristics in the transmission band compared to Model 2, which corresponds to the comparative example. This is thought to be because, in Model 1, a metal layer 40 is provided to cover the region 42 where the portion 60 connecting the common terminal Ant and the series resonator S13 of the signal wiring 14a overlaps with the receiving terminal Rx, thereby suppressing electromagnetic field coupling between the signal wiring 14a and the receiving terminal Rx.

[0056] As described above, according to Embodiment 1 and its modified examples, a plurality of elastic wave resonators 13 connected between a common terminal Ant and a transmitting terminal Tx are provided on the upper surface 10a of the substrate 10. In the regions 42 and 42a where the portion 60 of the signal wiring 14a connected to the common terminal Ant without going through the elastic wave resonators 13, or the portion 62 connected to the transmitting terminal Tx without going through the elastic wave resonators 13, and the receiving terminal Rx overlap, a metal layer 40 electrically connected to the ground terminal Gnd is provided between the upper surface 10a of the substrate 10 and the signal wiring 14a. By providing the metal layer 40, electromagnetic field coupling between the signal wiring 14a and the receiving terminal Rx in regions 42 and 42a can be suppressed. This makes it possible to suppress deterioration of electrical characteristics.

[0057] The portion 60 of the signal wiring 14a that connects to the common terminal Ant without going through the elastic wave resonator 13, or the portion 62 that connects to the transmitting terminal Tx without going through the elastic wave resonator 13, and the receiving terminal Rx have different potentials. Therefore, the metal layer 40 is provided between the upper surface 10a of the substrate 10 and the signal wiring 14a in the overlapping regions 42 and 42a where the receiving terminal Rx and the portions 60 and 62 of the signal wiring 14a that have different potentials from the receiving terminal Rx overlap. Thus, electromagnetic field coupling between the signal wiring 14a and the receiving terminal Rx in regions 42 and 42a can be suppressed, and deterioration of electrical characteristics can be suppressed.

[0058] Furthermore, according to Embodiment 1 and its modified form, a sealing portion 34 is provided on the upper surface 10a of the substrate 10, surrounding the multiple elastic wave resonators 13 and sealing the multiple elastic wave resonators 13 in the gap 32. The sealing portion 34 is electrically connected to the ground terminal Gnd. The metal layer 40 is electrically connected to the ground terminal Gnd by connecting to the sealing portion 34 on the upper surface 10a of the substrate 10. This enhances the electromagnetic shielding effect of the metal layer 40, and suppresses electromagnetic field coupling between the signal wiring 14a and the receiving terminal Rx in regions 42 and 42a.

[0059] In Example 1 and its modified form, the metal layer 40 may not be in contact with the sealing portion 34, but may be electrically connected to the ground terminal Gnd via a via wiring 16 connected to the metal layer 40. However, from the viewpoint of enhancing the electromagnetic shielding effect, it is preferable that the metal layer 40 is electrically connected to the ground terminal Gnd by being connected to the sealing portion 34.

[0060] Furthermore, according to Embodiment 1 and its modified version, the metal layer 40 is provided near the corner 37 of the sealing portion 34 in a plan view and is connected to the sealing portion 34 at two locations 41a and 41b located on either side of the corner 37. This enhances the electromagnetic shielding effect of the metal layer 40 and suppresses electromagnetic field coupling between the signal wiring 14a and the receiving terminal Rx in regions 42 and 42a. In Embodiment 1 and its modified version, the case in which the metal layer 40 is connected to the sealing portion 34 at two locations 41a and 41b is shown as an example, but it may also be connected to the sealing portion 34 at three or more locations located on either side of the corner 37.

[0061] Furthermore, according to Embodiment 1 and its modified form, the substrate 10 comprises a support substrate 11 having a lower surface 10b and a piezoelectric substrate 12 bonded to the support substrate 11 and having an upper surface 10a. The sealing portion 34 is provided in the area of ​​the support substrate 11 where the piezoelectric substrate 12 is not present. The metal layer 40 is provided extending from the piezoelectric substrate 12 to the support substrate 11 and is in contact with the sealing portion 34. When electromagnetic field coupling between the signal wiring 14a provided on the piezoelectric substrate 12 and the signal terminal provided on the lower surface of the support substrate 11 is suppressed, the metal layer 40 is provided on the piezoelectric substrate 12. In this case, by providing the metal layer 40 extending from the piezoelectric substrate 12 to the support substrate 11 and connecting it to the sealing portion 34, the metal layer 40 can be easily connected to the ground terminal Gnd.

[0062] Furthermore, according to Embodiment 1 and its modified version, a plurality of elastic wave resonators 23 are provided connected between the common terminal Ant and the receiving terminal Rx. The plurality of elastic wave resonators 13 form a transmit filter 70 connected between the common terminal Ant and the transmit terminal Tx, and the plurality of elastic wave resonators 23 form a receive filter 74 connected between the common terminal Ant and the receiving terminal Rx. In such a case, if electromagnetic field coupling occurs between the signal wiring 14a connected to the elastic wave resonator 13 and the receiving terminal Rx, the isolation characteristics may deteriorate. However, by providing the metal layer 40, electromagnetic field coupling can be suppressed, and the deterioration of the isolation characteristics can be suppressed.

[0063] Furthermore, according to Embodiment 1 and its modified form, in the region 42, 42a where the portions 60, 62 of the signal wiring 14a that connect to the common terminal Ant or the transmitting terminal Tx without going through the elastic wave resonator 13 overlap with the receiving terminal Rx, a metal layer 40 is provided between the upper surface 10a of the substrate 10 and the signal wiring 14a. When electromagnetic field coupling occurs between the portions 60, 62 of the signal wiring 14a that connect to the common terminal Ant or the transmitting terminal Tx without going through the elastic wave resonator 13 and the receiving terminal Rx, the impact of deterioration of isolation characteristics is significant. However, by providing the metal layer 40, electromagnetic field coupling can be suppressed, and the deterioration of isolation characteristics can be suppressed.

[0064] Furthermore, according to Example 1 and its modified form, the substrate 20 is provided with a plurality of elastic wave resonators 23 facing each other on the upper surface 10a of the substrate 10, separated by an air gap 32. In this case, the signal wiring 14a connected to the elastic wave resonators 13 and the receiving terminal Rx tend to overlap in a plan view. Therefore, in such cases, it is preferable to provide a metal layer 40.

[0065] Furthermore, according to Embodiment 1 and its variations, a transmitting filter 70 is formed by a plurality of elastic wave resonators 13, and a receiving filter 74 is formed by a plurality of elastic wave resonators 23. When electromagnetic field coupling occurs between the signal wiring 14a of the transmitting filter 70 and the receiving terminal Rx, it has a significant impact on the isolation characteristics. However, by providing the metal layer 40, electromagnetic field coupling can be suppressed, and the deterioration of the isolation characteristics can be suppressed.

[0066] Furthermore, according to Example 1 and its modified form, an insulating layer 46 is provided between the metal layer 40 and the signal wiring 14a to insulate the metal layer 40 from the signal wiring 14a. This makes it possible to suppress any adverse effects on the characteristics caused by the presence of the metal layer 40, even when the metal layer 40 is provided.

[0067] Furthermore, according to Example 1 and its modified form, the metal layer 40 is provided to cover the entire region 42, 42a where the portion 60, 62 of the signal wiring 14a that connects to the common terminal Ant or the transmitting terminal Tx without going through the elastic wave resonator 13 overlaps with the receiving terminal Rx. This makes it possible to suppress electromagnetic field coupling between the signal wiring 14a and the receiving terminal Rx in region 42, 42a. Note that the metal layer 40 may not cover a portion of region 42, 42a. The metal layer 40 may cover 50% or more of region 42, 42a, preferably 70% or more, more preferably 80% or more, and even more preferably 90% or more.

[0068] In Example 1 and its modified form, the metal layer 40 is provided in the region 42, 42a where the portions 60, 62 of the signal wiring 14a that connect to the common terminal Ant or the transmitting terminal Tx without going through the elastic wave resonator 13 overlap with the receiving terminal Rx. However, the invention is not limited to this case. The metal layer may also be provided in the region where the portion 60 of the signal wiring 14a that connects to the common terminal Ant without going through the elastic wave resonator 13 overlaps with the transmitting terminal Tx, or the metal layer may be provided in the region where the portion 62 of the signal wiring 14a that connects to the transmitting terminal Tx without going through the elastic wave resonator 13 overlaps with the common terminal Ant. [Examples]

[0069] The circuit diagram and cross-sectional view of the elastic wave device 200 according to Example 2 are the same as those in Figures 1 and 2 of Example 1, so their explanation is omitted. Figures 11(a) and 11(b) are plan views of the substrates 10 and 20 in the elastic wave device 200 according to Example 2. Figure 11(a) is a plan view of the top surface 20a of the substrate 20 seen from above, and Figure 11(b) is a plan view of the top surface 10a of the substrate 10 seen from above. As shown in Figures 11(a) and 11(b), in Embodiment 2, a metal layer 40 is provided between the upper surface 10a of the substrate 10 and the signal wiring 14a in the region 42 where the portion 60 connecting the common terminal Ant and the series resonator S12 of the signal wiring 14a overlaps with the receiving terminal Rx in a plan view. In addition, a metal layer 40a is provided between the upper surface 10a of the substrate 10 and the signal wiring 14a in the region 42b where the portion 64 connecting the series resonators S11 and S12 and the parallel resonator P12 overlaps with the common terminal Ant in a plan view. The metal layer 40a, like the metal layer 40, is electrically connected to the ground terminal Gnd by connecting to the sealing portion 34. An insulating layer 46a is provided between the metal layer 40a and the signal wiring 14a to insulate the metal layer 40a from the signal wiring 14a. The other configurations are the same as in Embodiment 1, so their description is omitted.

[0070] According to Embodiment 2, in the region 42b where the portion 64 of the signal wiring 14a connected to the transmitting terminal Tx and the common terminal Ant via the elastic wave resonator 13 overlaps with the common terminal Ant, a metal layer 40a electrically connected to the ground terminal Gnd is provided between the upper surface 10a of the substrate 10 and the signal wiring 14a. By providing the metal layer 40a, electromagnetic field coupling between the signal wiring 14a and the common terminal Ant in region 42b can be suppressed. This makes it possible to suppress the deterioration of electrical characteristics.

[0071] Furthermore, according to Embodiment 2, the metal layer 40a is provided to cover the entire region 42b where the portion 64 of the signal wiring 14a connected to the transmitting terminal Tx and the common terminal Ant via the elastic wave resonator 13 overlaps with the common terminal Ant. This makes it possible to suppress electromagnetic field coupling between the signal wiring 14a and the common terminal Ant in region 42b. Note that the metal layer 40a may not cover a part of region 42b. The metal layer 40a may cover 50% or more of region 42b, preferably 70% or more, more preferably 80% or more, and even more preferably 90% or more.

[0072] In Example 2, the case where both metal layer 40 and metal layer 40a are provided is shown as an example, but it is also possible for only one of the metal layers 40 or 40a to be provided.

[0073] In Example 2, the metal layer 40a was provided in the region 42b where the portion 64 connecting the elastic wave resonators 13 of the signal wiring 14a overlaps with the common terminal Ant, but this is not the only example. The metal layer may also be provided in the region where the portion connecting the elastic wave resonators 13 of the signal wiring 14a overlaps with the transmitting terminal Tx, or in the region where the portion connecting the elastic wave resonators 13 of the signal wiring 14a overlaps with the receiving terminal Rx.

[0074] In Examples 1 and 2, the transmitting filter 70 is formed on the substrate 10, and the receiving filter 74 is formed on the substrate 20, overlapping the transmitting filter 70 in a plan view. However, the invention is not limited to this case. It is also possible that the substrate 20 is not provided on the substrate 10, and both the transmitting filter 70 and the receiving filter 74 are provided on the substrate 10. Furthermore, the invention is not limited to the case where both the transmitting filter 70 and the receiving filter 74 are provided; it is also possible that only one of the filters is formed on the substrate 10. In addition, although Examples 1 and 2 show the ladder type filter as an example, a multimode type filter is also possible.

[0075] In Examples 1 and 2, the case in which the elastic wave resonator 23 is provided on the upper surface 20a of the substrate 20 is shown as an example, but it may also be provided on the lower surface 20b of the substrate 20. In this case, both elastic wave resonators 13 and 23 are sealed in the gap 32 between the substrate 10 and the substrate 20. The shield layer 28 is located between the elastic wave resonator 13 and the elastic wave resonator 23 and is provided in the gap 32.

[0076] Although embodiments of the present invention have been described in detail above, the present invention is not limited to these specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention as described in the claims. [Explanation of symbols]

[0077] 10, 20 circuit boards 10a, 20a top surface 10b, 20b bottom side 11, 21 Support substrate 12, 22 Piezoelectric substrate 13, 23 Elastic wave resonators 14, 24 Wiring 14a, 24a signal wiring 14b, 24b Ground wiring 15 terminals Via wiring 16, 26 17 Pillar 30 Lid 32, 33 void 34, 36 Sealing part 34a, 36a Annular metal layer 34b, 36b Handa Formation 37 Corner 40, 40a metal layer Locations 41a and 41b 46, 46a Insulating layer 42, 42a, 42b area 60, 62, 64 parts 70 Sending Filter 72 Series Path 74 Receiving Filter 76 Series Path Ant Common Terminal Tx Transmitter Terminal Rx receiving terminal Gnd Ground terminal 100, 110, 200, 500 elastic wave devices

Claims

1. A first substrate having a first surface and a second surface opposite to the first surface, Multiple terminals provided on the second surface, A plurality of first elastic wave resonators are provided on the first surface and connected between the first signal terminal and the second signal terminal among the plurality of terminals, A signal wiring provided on the first surface and connected to the plurality of first elastic wave resonators, A metal layer is provided between the first surface and the signal wiring in at least one of the following regions: a first region where a first portion of the signal wiring that connects to either the first signal terminal or the second signal terminal without going through the plurality of first elastic wave resonators overlaps with a signal terminal other than the one of the plurality of terminals; and a second region where a second portion of the signal wiring that connects to the first signal terminal and the second signal terminal via at least one of the plurality of first elastic wave resonators overlaps with a signal terminal among the plurality of terminals; and a metal layer electrically connected to the ground terminal among the plurality of terminals. The device comprises a sealing portion provided on the first surface surrounding the plurality of first elastic wave resonators, which seals the gap between the plurality of first elastic wave resonators, The sealing portion is electrically connected to the ground terminal. The metal layer is electrically connected to the ground terminal by contacting the sealing portion on the first surface, forming an elastic wave device.

2. The elastic wave device according to claim 1, wherein the metal layer is provided near the corner of the sealing portion in a plan view and is connected to the sealing portion at at least two locations located on either side of the corner.

3. The first substrate comprises a support substrate having the second surface and a piezoelectric substrate having the first surface bonded to the support substrate, The sealing portion is provided in an area on the support substrate where the piezoelectric substrate is not present. The elastic wave device according to claim 1 or 2, wherein the metal layer is provided extending from the piezoelectric substrate to the support substrate and in contact with the sealing portion.

4. The system comprises a plurality of second elastic wave resonators connected between the first signal terminal and the third signal terminal among the plurality of terminals, The plurality of first elastic wave resonators form a first filter connected between the first signal terminal and the second signal terminal. The elastic wave device according to claim 1 or 2, wherein the plurality of second elastic wave resonators form a second filter connected between the first signal terminal and the third signal terminal.

5. The first region is the region where the first portion and the third signal terminal overlap. The elastic wave device according to claim 4, wherein the metal layer is provided between the first surface of the first substrate and the signal wiring in the first region.

6. The second region is the region where the second portion and the first signal terminal overlap. The elastic wave device according to claim 4, wherein the metal layer is provided between the first surface of the first substrate and the signal wiring in the second region.

7. The first substrate comprises a second substrate facing the first surface of the first substrate with a gap in between, The elastic wave device according to claim 4, wherein the plurality of second elastic wave resonators are provided on the second substrate.

8. The first signal terminal is a common terminal, the second signal terminal is a transmit terminal, and the third signal terminal is a receive terminal. The first filter is a transmit filter connected between the common terminal and the transmit terminal, The elastic wave device according to claim 4, wherein the second filter is a receiving filter connected between the common terminal and the receiving terminal.

9. The elastic wave device according to claim 1 or 2, further comprising an insulating layer provided between the metal layer and the signal wiring, which insulates the metal layer from the signal wiring.

10. A substrate having a first surface and a second surface opposite to the first surface, Multiple terminals provided on the second surface, A plurality of elastic wave resonators provided on the first surface, A signal wiring provided on the first surface and connected to the plurality of elastic wave resonators, A metal layer is provided between the first surface and the signal wiring in the region where the signal terminals among the plurality of terminals and the portion of the signal wiring that has a different potential from the signal terminals overlap, and which is electrically connected to the ground terminal among the plurality of terminals. The device comprises a sealing portion provided on the first surface surrounding the plurality of elastic wave resonators, which seals the gap between the plurality of elastic wave resonators, The sealing portion is electrically connected to the ground terminal. The metal layer is electrically connected to the ground terminal by contacting the sealing portion on the first surface, forming an elastic wave device.

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